1. Field of the Invention
The present invention relates to a steering lock for an automotive vehicle and more specifically to a steering lock which is responsive to a number of sensors and which ensures that the steering cannot be locked without a predetermined number of conditions being met.
2. Description of the Prior Art
In commonly used engine ignition key arrangements it is usual to enable the key to be turned to a plurality of different positions such as LOCK, OFF ACC and ON. When the key turned slightly past ON, the engine is cranked by the energization of a cell or starter motor. The ignition key cylinder is normally mounted on the steering column so as to enable the steering to be locked and prevent steering of the vehicle.
JP-A-57-164841 discloses an arrangement wherein a safety button is provided which must be pressed before the steering can be locked by allowing a bolt from being permitted to assume a position wherein it engages the steering shaft in a manner to prevent rotation thereof and before the key can be withdrawn from the key cylinder. Viz., with this arrangement in order to stop the engine and withdraw the key it is necessary to turn the key from the ON position to the ACC (accessory) position, press the button and then rotate key to the LOCK position. This provides a safeguard against possible locking of the steering shaft under conditions wherein it is not desired and can suddenly inhibit steering of the vehicle in a potentially dangerous manner.
However, this arrangement has suffered from the drawbacks that in addition to the intricate lock mechanism it is necessary to include a member which operatively connected with the key cylinder. This member is can, depending on the position in which the key is set, project and a radially extending arcuate portion into a slot formed in a shaft operatively connected with the safety button and thereby lock the shaft to prevent actuation of the button and accidental locking of the steering. This arrangement, though must be included in the housing in which the key cylinder is disposed and therefore complicates both the design and manufacture of the housing.